JPS6213880Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a dump truck loading platform device which is provided with a rear door that automatically opens and closes in response to the ups and downs of the loading platform.

In dump trucks, the rear door of the loading platform bucket is generally of the type in which the lower part rotates to open around its upper edge axis when the load is being discharged. In most cases, the rear door is manually disengaged when the load such as earth and sand, metal scraps, wood chips, etc. is discharged from the loading platform. In such a dump truck loading platform device in which the rear door is manually opened, it takes effort and time to open, close, engage and disengage the rear door, which is extremely troublesome and inefficient. In addition, in some cases, the cargo may be ejected if the rear door is opened incorrectly. In order to solve the above-mentioned problems in releasing the rear door manually, we developed a link mechanism that opens and closes the rear door in response to the ups and downs of the loading bucket, as described in Japanese Patent Publication No. 47-3285. The dump trucks installed have been announced.

Although such an automatic opening/closing device for the rear door of the dump truck loading platform can perform suitable operations during cargo handling, the inventors of the present invention
With the aim of providing an automatic opening/closing device for the rear door of a dump truck that uses a rotating door system instead of the sliding door described in No. 3285 and has a simpler structure, various research studies were conducted and the present invention was completed.

The dump truck loading platform device of the present invention is provided with inclined guides each having a rearward upward slope at the upper rear ends of both side walls of the dump truck loading platform, and engaging pins protruding and fixed laterally at the lower rear ends, respectively. The fitting portions attached to the tips of the fixed arms, which are provided at both ends of the upper part of the rear door so as to protrude forward at an angle of about 90 degrees, are movably fitted to each of the above-mentioned inclined guides, and the rear door is fixed. At both ends of the lower part, engaging hooks which are respectively latched onto the respective engaging pins are attached with the extra length of the rear door remaining below the mounting part, and the engaging parts are fitted into the inclined guide. When the hook is moved rearward, the engagement hook is released from the engagement pin, and when the loading bucket is tilted to unload the loaded object, the rear door automatically opens in response. When the rear door is opened and the cargo bucket is restored, the rear door closes and latches automatically.

Hereinafter, an example in which the loading platform device of the present invention is implemented in a dump type road lugger will be described in detail with reference to the drawings.

FIG. 1 is a side view of a dump-type road lugger to which the loading bucket truck of the present invention (hereinafter simply referred to as bucket truck) is attached, and FIG. 2 is an enlarged side view showing the rear door of the bucket truck.

The dump truck chassis 1 has a bucket 2 having side walls.
is mounted so that it can be tilted up and down by a suitable up-and-down device such as a cylinder device (not shown). 3 is a tilting fulcrum shaft of the bucket cart 2. Reference numeral 4 denotes a rear door of the bucket bag 2, and arms 5 are fixed to both ends of the upper part of the door 4 in a substantially square shape facing forward.
When the arm 5 is fixed to the rear door 4, it is fixed at a right angle or at an angle close to it, as shown in the illustrated example.
Guide mounting plates 7 are provided at the upper rear ends of both side walls 6 of the bucket 2, respectively. Reference numeral 8 denotes a guide consisting of a long hole provided in the guide mounting plate.
When the bucket 2 is held horizontally, it slopes upward toward the rear, but the angle of inclination is the same as when the bucket 2 starts to fall when the bucket 2 is tilted to discharge the loaded material. The axis of the guide 8 is set to substantially coincide with the horizontal line at the inclination angle. Reference numeral 9 denotes engaging hooks provided inwardly at the lower portions of both ends of the rear door 4, and an extra length portion 10 of the rear door is provided below the attachment of the hooks. The extra length 10
The length is such that the rear door 4 is pushed rearward by the loaded object based on the tilting of the bucket 2, and the fitting pins 11 attached to the tips of the arms 5 and fitted to the respective guides 8 are guided. As the rear door 4 rotates around the point of contact between the lowermost end 4' of the rear door 4 and the rear end of the side wall of the bucket 2, the tip of the engagement hook 9 is attached to the bucket 2. Each engagement pin 12 is provided laterally at the rear lower part of both side walls 6.
Any length is sufficient as long as it can be easily displaced toward the upper outer periphery of the engaging pin 12, and can be determined as appropriate depending on the installation position of the engaging pin 12.

In the present invention, the guide 8 provided at the upper rear end of both side walls 6 of the bucket bag 2 is formed by a rolling guide frame instead of being formed by a long hole as in the illustrated example, and the fitting pin 11 is formed by a rolling roller. It can also be fitted in such a way that it can roll freely. The length of the guide 8 is not particularly limited, but should be long enough to cause the rearward movement of the upper part of the rear door 4 to disengage the engagement end of the engagement hook 9 from the engagement pin 12 when the bucket 2 is tilted. The length is such that the rear door 4 can rotate enough to displace the rear door 4 upward.

The dump truck loading platform device of the present invention is constructed as described above, and its operation will be further described below. When unloading steel cuttings, soil, sand, etc. loaded and stored in the bucket 2 of the dump truck loading platform, when the bucket 2 is tilted using an appropriate tilting device such as a cylinder (not shown), the axis of each guide 8 is tilted. reaches the horizontal direction and further changes to a reverse slope. Therefore, the rear door 4 is pushed rearward by the cargo, and the fitting pin 11, which is slidably fitted into the guide 8, slides within the guide 8. At this time, the lower extra length end 4' of the rear door 4 comes into contact with the lower rear end of the bucket side wall 6, and the upper part of the rear door 4 is rotated rearward about the contact point as the center of rotation. Thus, the engaging end of the engaging hook 9 slides on the circumferential surface of the engaging pin 12 and reaches the upper side of the engaging pin, and the engagement is released, the lower part of the rear door 4 is released, and the cargo is discharged.

On the other hand, after the load is discharged, by restoring the bucket 2 horizontally, the engaging hook 9 is engaged with the engaging pin 12 by the reverse operation to the above, and the engaging pin 11 is moved to the lowest position of the guide 8. The rear door is securely closed due to its own weight.

Since the dump truck loading platform device of the present invention has the above-mentioned configuration, its structure is extremely simple and easy to process, and the rear door can be opened and closed automatically without the need for a special power device. In addition, since the opening and closing of the rear door is rationally linked to the tilting of the bucket, there is no erroneous movement due to operator forgetfulness, and work can be performed extremely safely.

[Brief explanation of drawings]

FIG. 1 is a side view of a dump truck equipped with the cargo handling device of the present invention, and FIG. 2 is a detailed view showing the rear door mounting structure. 2; Bucket, 4; Rear door, 5; Arm, 8; Guide, 9; Engagement hook, 11; Fitting pin, 12; Engagement pin.

Claims (1)

[Scope of utility model registration request] Inclined guides 8 having rearward upward slopes are provided at the upper rear ends of both side walls 6 of the dump truck loading bucket 2, and engagement pins 12 are provided and fixed to the rear lower portions to project sideways, and the upper part of the rear door 4 is fixed. The fitting pins 11 attached to the tips of the fixed arms 5, which are provided at both ends to protrude forward at an angle of about 90 degrees, are movably fitted into the respective inclined guides 8, and the rear door is fixed. At both ends of the lower part, engaging hooks 9 which are respectively latched onto the respective engaging pins 12 are attached with the extra length of the rear door 4 remaining below the mounting portion, and the engaging pins 11
The dump truck platform device is characterized in that the engaging hook 9 is released from being latched to the engaging pin by moving rearward within the inclined guide 8.